CVE-2019-25549 Overview
CVE-2019-25549 is a denial of service vulnerability affecting VeryPDF PCL Converter version 2.7. The vulnerability allows local attackers to crash the application by supplying an excessively long password string. Specifically, attackers can trigger a buffer overflow by entering a 3000-byte password in the PDF Security encryption fields, causing the application to crash when processing PCL files.
Critical Impact
Local attackers can cause application crashes and denial of service by exploiting improper bounds checking in the PDF Security password field, disrupting document conversion workflows.
Affected Products
- VeryPDF PCL Converter 2.7
Discovery Timeline
- 2026-03-21 - CVE CVE-2019-25549 published to NVD
- 2026-03-23 - Last updated in NVD database
Technical Details for CVE-2019-25549
Vulnerability Analysis
This vulnerability is classified under CWE-787 (Out-of-Bounds Write), which occurs when the software writes data past the end, or before the beginning, of the intended buffer. In the context of VeryPDF PCL Converter 2.7, the application fails to properly validate the length of user-supplied password input in the PDF Security encryption fields before copying it to a fixed-size buffer.
When a user enters a password exceeding the expected buffer size (approximately 3000 bytes), the application attempts to process this input without adequate boundary checks. This results in memory corruption that leads to an application crash, effectively creating a denial of service condition.
The vulnerability requires local access to the system where VeryPDF PCL Converter is installed. An attacker would need to interact with the application's GUI or potentially supply malicious configuration data that triggers the vulnerable code path during PCL file processing.
Root Cause
The root cause of this vulnerability is insufficient input validation and improper bounds checking when handling password strings in the PDF Security encryption feature. The application allocates a fixed-size buffer for password storage but does not enforce length restrictions on user input before copying data into this buffer. This classic buffer overflow pattern allows attackers to overwrite adjacent memory regions, corrupting application state and causing a crash.
Attack Vector
The attack requires local access to the target system. An attacker must interact with the VeryPDF PCL Converter application, specifically the PDF Security encryption configuration. By entering an excessively long password string (approximately 3000 bytes) in the password field, the attacker can trigger the buffer overflow condition.
The attack sequence involves:
- Opening VeryPDF PCL Converter 2.7
- Navigating to the PDF Security or encryption settings
- Entering a password string of approximately 3000 bytes
- Initiating a PCL file conversion operation
- The application crashes due to buffer overflow
Technical details and proof-of-concept information are available via the Exploit-DB #46872 advisory.
Detection Methods for CVE-2019-25549
Indicators of Compromise
- Unexpected application crashes of VeryPDF PCL Converter during document processing operations
- Windows Error Reporting (WER) crash dumps indicating pclcnv.exe or related process crashes with access violation errors
- Event log entries showing application faults with exception codes related to memory access violations (0xC0000005)
Detection Strategies
- Monitor application crash reports and Windows Error Reporting for VeryPDF PCL Converter crashes with memory access violations
- Implement application whitelisting policies to restrict execution of vulnerable versions
- Deploy endpoint detection rules to identify processes exhibiting buffer overflow crash signatures
Monitoring Recommendations
- Enable Windows Error Reporting collection for forensic analysis of application crashes
- Monitor system event logs for repeated application fault events associated with VeryPDF products
- Configure SentinelOne endpoint agents to alert on crash patterns indicative of exploitation attempts
How to Mitigate CVE-2019-25549
Immediate Actions Required
- Restrict access to VeryPDF PCL Converter 2.7 to trusted users only
- Consider replacing or upgrading the application if a patched version is available from the vendor
- Implement application control policies to limit exposure to this vulnerability
- Monitor the VeryPDF website for security updates or newer versions
Patch Information
No official patch information is currently available from the vendor. Users should contact VeryPDF directly or monitor the VeryPDF Home Page for security updates. The VulnCheck Advisory on VeryPDF provides additional guidance on this vulnerability.
Workarounds
- Limit local access to systems running VeryPDF PCL Converter 2.7 to trusted personnel only
- Disable or restrict access to the PDF Security encryption feature if not required for business operations
- Consider using alternative PCL conversion tools that do not contain this vulnerability
- Implement application sandboxing to contain potential crashes and prevent broader system impact
# Configuration example - Restrict application access via Windows AppLocker
# Create a deny rule for non-administrative users
# PowerShell example to check installed VeryPDF version
Get-ItemProperty "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\*" |
Where-Object { $_.DisplayName -like "*VeryPDF*PCL*" } |
Select-Object DisplayName, DisplayVersion
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
